Repeatability and reproducibility of optical biometry implemented in a new optical coherence tomographer and comparison with a optical low-coherence reflectometer.

PURPOSE

To examine the repeatability and reproducibility of biometry provided by a new anterior-posterior segment spectral-domain optical coherence tomography (SD-OCT) device (Revo NX) and compare it with that provided by a validated optical low-coherence reflectometry (OLCR) biometer (Lenstar LS 900).

SETTING

Hygeia Clinic, Gdańsk, Poland.

DESIGN

Prospective evaluation of diagnostic test.

METHODS

The axial length (AL), lens thickness (LT), central corneal thickness (CCT), and anterior chamber depth (ACD) (corneal epithelium to lens) were measured in eyes of volunteers. Two skilled operators obtained 3 measurements in random order with the SD-OCT device. Repeatability was calculated for each observer, while reproducibility was assessed by a change in observer. To compare agreement between the SD-OCT device and OLCR device, the first observer took 3 measurements with both devices.

RESULTS

The study evaluated 63 eyes of 63 volunteers. The mean AL measurement (+0.11 mm ± 0.02 [SD]) and mean ACD measurement (0.05 ± 0.04 mm) were significantly higher with the SD-OCT device than with the OLCR device; the CCT measurements did not differ between the devices. A very strong correlation was found for all parameters, while Bland-Altman analysis showed narrow 95% limits of agreement for AL (0.06 to 0.15 mm), ACD (-0.02 to 0.12 mm), LT (-0.23 to 0.17 mm), and CCT (-7.83 to 6.17 μm).

CONCLUSIONS

The new SD-OCT device provided repeatable and reproducible AL, ACD, LT, and CCT measurements. The results with the SD-OCT device showed strong correlations with those obtained with the OLCR device. However, the AL and ACD measurements of the 2 devices cannot be considered interchangeable.